This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Infancy is a critical developmental period, particularly for the development of secure attachment, which provides the cornerstone of healthy emotional functioning in childhood (Bretherton, 1992). Humorous exchanges include the responsive and synchronous interactions that are known to promote secure attachment. Despite this, little is known regarding infant humor development, particularly within the first 6 months of life and as a predictor of early attachment. The present study will describe humor development in 3 to 6 month old infants using naturalistic observation, and examine the relationship between infant humor, temperament and attachment at one year. Mothers of twenty infants will be trained to record detailed descriptions of humor perception and creation in their babies over 12 weeks, and will be videotaped during playful interaction once per month for four consecutive months. Reddy's (2001) behavioral scheme will be used to code infant humor. It is hypothesized that humor in 3 to 6 months old infants will be correlated with positive indices of infant temperament on the Infant Behavior Questionnaire-Revised (Gartstein &Rothbart, 2003), and will predict attachment quality on the Observer Attachment Q-Sort (Waters &Deane, 1985) at one year. This study will add to the small body of research on infant humor as a psychosocial process, and as it contributes to the important task of attachment.